Many of the 30-odd conflicts - all civil wars - are popularly attributed to "ethnic" divisions, but, the report argues, these are intensified by more fundamental disputes over basic resources. The report, Fighting for Survival, argues that stabilising population, reducing social inequalities, conserving soil and water and slowing global warming are now more important for preserving international security than conventional military forces.
The report has proved timely, as renewed conflict - which it argues has its origins in population growth and land shortage - has erupted in the Great Lakes region of Africa. Contracts for oil exploration around the Falklands were also announced yesterday. The possibility of large oil deposits in the area was undoubtedly one factor fuelling the dispute over sovereignty between Britain and Argentina.
However, pressure on resources is more likely to lead to internal conflict than conflict between states, the report says. "The greatest threats to security today come from within nations, not from invading armies," said Michael Renner, the author of the report, published by the Worldwatch Institute in Washington. "These new threats are the real root of what some have called the 'new world disorder'."
The report cites numerous examples of how, as population pressures build and local resources collapse, people resort to ethnic, religious or other identities for protection. Among the most vulnerable are 400 million people in developing countries who eke out a meagre living in lands where the ecology is very fragile.
Some 300 billion hectares - about 70 per cent of potentially productive agricultural land - has already been turned into desert. As agricultural land is degraded it can no longer support a growing population. And in Latin America, wealthy landowners control much of the best land, so that, as the population expands, poor peasants are forced on to marginal land.
Among the main potential causes of conflict are water shortage and global warming, which can lead to flooding. Conflicting claims on the Euphrates have led to tension between Turkey, Syria and Iraq. Ethiopia's plans to divert the upper Nile for irrigation and hydro-electric power could also bring it into conflict with Egypt, which is totally dependent on the river.
Too much water could also be a problem. "Threats to security could be exacerbated by coming changes in the world's climate caused by the build- up of greenhouse gases," the report warns. "This is projected to trigger an increase in heatwaves, hurricanes, floods, droughts, wildfires, and a rise in sea level that could displace 70 million people in China alone."
The report recommends diverting military spending to addressing the environmental and social problems that cause conflict. It estimates that $200bn is needed for urgent action, which could be provided by diverting some of the $800bn-a-year global military budget. The money should be spent on preserving and managing forests, water and soil - the resources which underpin most rural economies, and redistributing land.
"Security in the Nineties has less to do with how many tanks or soldiers," Mr Renner concludes, "and more with how well it protects its arable lands and watersheds, and whether it is able to reduce social pressures. National leaders would do well to focus less on the symptoms of today's conflicts and more on their root causes."
Battle in the land of the bougainvillaea kills thousands
Bougainville is probably the clearest example of an environmentally induced conflict, in which some 1,000 people have died in the past seven years.
Fighting erupted when rebels demanded independence from Papua, New Guinea, after a dispute caused by massive pollution from a copper mine at Panguna. Water was polluted, waterways became clogged and fish died as a result of the debris from the mine, which polluted one-fifth of the island.
In 1988 local people demanded changes and compensation.
By the end of the year the mine was attacked by saboteurs, and in May 1989 it was closed.
The conflict continues, however.
Chiapas, in Mexico, central America, has seen a rebellion largely fuelled by logging, oil and gas exploration. As these resources were extracted, large numbers of poor peasants were pushed into the Lacandon rainforest.
When the rainforest was cleared, the land quickly deteriorated, pushing the peasants further into the forest. Tree cover declined from 90 per cent in 1960 to 30 per cent today.
As the situation deteriorated further, Zapatista rebels - made up largely of the poorer peasants - staged an armed uprising in January 1994 to protest against the government's decision to abandon a historic commitment to land reform.
This led to violent clashes with Mexican government troops, which have continued to the present day.
Sudan has long been divided into the Muslim north and the Christian south, but this cultural and ethnic divide did not become aassociated with conflict until environmental factors intervened.
From the late Seventies, ill-conceived farming projects began to cause severe soil degradation, eating away at the fertile land in the south. When the crops failed, more land was cultivated.
People in the south, unable to make a living, were displaced and moved into urban slums, particularly in the capital, Khartoum. This movement of cheap labour benefited the north of the country, at the expense of the south. In 1983, fighting started, and the country began sliding into civil war.
Rwanda, Burundi and Zaire have all seen ferocious fighting, which has recently erupted again.
The civil war in Rwanda was fuelled by population growth which put immense pressure on the land. Over-cultivation diminished soil fertility, cutting harvests by one-third between 1990 and 1993. The resulting economic desperation allowed Hutu extremists to play up existing ethnic tensions, culminating in the massacres of 1994.
Economic decline was a major factor in producing a disillusioned young generation with few prospects; enlistment in militia groups seemed an attractive option. The subsequent flood of refugees into Zaire exacerbated environmental damage.Reuse content